Analysis of monoamines, adenosine and GABA in tissues of the land snail Helix lucorum and lizard Agama stellio stellio during hibernation

Michaelidis, B; Loumbourdis, NS; Kapaki, E

dc.contributor.author	Michaelidis, B	en
dc.contributor.author	Loumbourdis, NS	en
dc.contributor.author	Kapaki, E	en
dc.date.accessioned	2014-03-01T01:52:02Z
dc.date.available	2014-03-01T01:52:02Z
dc.date.issued	2002	en
dc.identifier.issn	0022-0949	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/26539
dc.subject	land snail	en
dc.subject	Helix lucorum	en
dc.subject	lizard	en
dc.subject	Agana stellio stellio	en
dc.subject	neurotransmitter	en
dc.subject	hibernation	en
dc.subject	metabolic depression	en
dc.subject.classification	Biology	en
dc.subject.other	GAMMA-AMINOBUTYRIC-ACID	en
dc.subject.other	CENTRAL-NERVOUS-SYSTEM	en
dc.subject.other	ANOXIC TURTLE BRAIN	en
dc.subject.other	LONG-TERM ANOXIA	en
dc.subject.other	CRUCIAN CARP	en
dc.subject.other	METABOLIC DEPRESSION	en
dc.subject.other	IMMUNOREACTIVE NEURONS	en
dc.subject.other	LYMNAEA-STAGNALIS	en
dc.subject.other	POND SNAIL	en
dc.subject.other	AMINO-ACID	en
dc.title	Analysis of monoamines, adenosine and GABA in tissues of the land snail Helix lucorum and lizard Agama stellio stellio during hibernation	en
heal.type	journalArticle	en
heal.language	English	en
heal.publicationDate	2002	en
heal.abstract	The aim of the present study was to determine the levels of monoamines, GABA and adenosine in the brain, heart and haemolymph of the land snail Helix lucorum and in the brain, heart and blood of lizard Agama stellio stellio during long-term hibernation. We measured levels of the monoamines serotonin (5-HT) and its main metabolite 5-hydroxyindole-3-acetic acid (5-HIAA), dopamine (DA) and its metabolites dihydroxyphenylacetic acid (DOPAC) and homovanilic acid (HVA), norepinephrine (NE) and epinephrine (E). The most abundant amines detected in the brain and heart of active H. lucorum were 5-HT and DA. Of the metabolites examined only 5-HIAA was found in the brain. NE was found at very low levels but only in the brain, while E was not detected in the brain and heart. The levels of 5-HT and 5-HIAA increased in the brain and heart of H. lucorum within the first months of hibernation, showing a significant decrease thereafter. The levels of DA did not change during hibernation. The results indicated that 5-HT might be involved in preparing snails for entry into hibernation. GAGA was only found in the brain of H. lucorum, and the levels were low; these levels remained during hibernation. Adenosine was present in brain and heart of H. lucorum, and during hibernation, the level of adenosine decreased significantly in the brain but remained steady in the heart. The monoamines 5-HT, DA and NE were present in the brain of active lizards A. stellio stellio, whereas E was found only at very low levels. Moreover, the metabolites 5-HIAA, DOPAC and HVA were detected in the brain of active lizards. The monoamines 5-HT, DA, NE and E were also detected in the heart and blood of active lizards. During hibernation the levels of these four monoamines were decreased significantly in the brain and heart of A. stellio stellio. In contrast, the levels of E increased in the heart and blood of hibernating lizards. Adenosine was detected in both heart and brain of active lizards, but hibernation caused a marked decrease in its levels at both tissues. GAGA was found at higher levels than monoamines and adenosine in the brain of active lizards, and hibernation caused a significant increase in its levels, indicating an important role of GAGA in inhibition of neuronal activity in hibernating lizards.	en
heal.publisher	COMPANY OF BIOLOGISTS LTD	en
heal.journalName	JOURNAL OF EXPERIMENTAL BIOLOGY	en
dc.identifier.isi	ISI:000175323300009	en
dc.identifier.volume	205	en
dc.identifier.issue	8	en
dc.identifier.spage	1135	en
dc.identifier.epage	1143	en